Confined space emergencies should not occur. A well prepared and conducted entry into a confined space by a properly qualified crew with the appropriate resources should allow a safe and successful entry to be conducted. This unfortunately does not always occur. Also, the strict definition of emergencies used by OSHA in 1910.1461 and ANSI Z117.1-20032 mean that occasionally even competent crews will experience at least minor emergencies.
The primary goal must be safe entries and the prevention of emergencies. The majority of our efforts should be dedicated to accomplishing this. We must, however, be prepared for emergencies.
Effective preparation can make the difference between keeping emergencies minor and resolving them quickly and effectively or allowing them to turn into fatalities.
Emergencies may occur in several different categories.
Failure of monitoring equipment
Failure of hazard control measures
Introduction of an unforeseen hazard
Problems with individual entrants
Problems within the space
Minor emergencies where entrants are capable of leaving the space without assistance
Minor emergencies where entrants need some assistance but are not in serious danger
Major emergencies where an entrant is in serious danger from a personal medical problem
Major emergencies where conditions in the space are life threatening
Failure of hazard control measures could cause either minor or major emergencies depending upon which type of hazard control is involved. If a ventilation system stops working effectively it is easy to notice the failure immediately and take appropriate action to restore ventilation. Even if the problem cannot be solved immediately in most spaces there would be sufficient time to evacuate the safe before the atmosphere became dangerous. Other hazard control failures could lead to major injuries or deaths in an instant. If lockout has not been completed properly on an agitator motor our first indication of the failure of the hazard control may be the agitator blade striking an entrant. If a blank installed in a pipe being isolated is made of the wrong material our first awareness that it has failed will be the material flowing into the space and exposing the entrants.